摘要
以野生天冬块根为原料,通过水提醇沉法得到天冬多糖(asparagi radix polysaccharide,ARP),研究其理化性质和流变学特性。结果表明,ARP中总糖含量为(93.75±1.68)%,总糖醛酸含量为(26.99±0.97)%,酯化度为(38.2±0.14)%,重均分子量为730 kDa。ARP由鼠李糖(Rha)、阿拉伯糖(Ara)、半乳糖(Gal)、葡萄糖(Glc)、木糖(Xyl)、甘露糖(Man)6种单糖和半乳糖醛酸(GalA)、葡萄糖醛酸(GlcA)2种糖醛酸组成,物质的量比是0.27∶1.39∶4.42∶12.66∶1∶0.50∶4.83∶0.29。扫描电镜和原子力显微镜观察发现ARP构象为球形聚集状,表面结构紧致平滑。X-衍射结果表明ARP结晶度低。热学特性结果显示ARP具有较高的热稳定性。流变学结果表明,温度、质量浓度、盐离子(Na^(+)和Ca^(2+))的种类和浓度对ARP的黏度和剪切应力均有影响,且作用方式不同。ARP溶液的黏度随着剪切速率的增加呈现下降趋势,出现剪切稀化现象,表明ARP溶液属于非牛顿流体。研究结果为天冬多糖在食品和医药等领域的开发利用提供理论依据。
The root tuber of wild asparagi radix was used as raw material for the extraction of asparagi radix polysaccharide(ARP)by water extraction and alcohol precipitation method.The physicochemical and rheological properties of ARP were studied.The purity,the average molecular weight(M w),the esterification degree and the chemical composition of polysaccharides were determined.Additionally,the crystallization properties,thermal properties and the effects of different factors on the apparent viscosity and shear stress of ARP were also been studied.In the meantime,the dynamic rheological properties of ARP were explored.The results indicated that the content of total polysaccharide,the total uronic acid content,the esterification degree and the average molecular weight of polysaccharide were(93.75±1.68)%,(26.99±0.97)%,(38.2±0.14)%and 730 kDa respectively.ARP was composed of six monosaccharides(Rha,Ara,Gal,Glc,Xyl,Man)and two uronic acids(GalA,GlcA)in a molar ratio of 0.27∶1.39∶4.42∶12.66∶0.50∶0.50∶4.83∶0.29.The results of scanning electron microscope and atomic force microscope showed that the conformation of ARP was spherical and aggregated,and the surface was compact and smooth.Moreover,X-ray diffraction illustrated that the crystallinity of ARP was low.The thermal properties suggested that ARP had high thermal stability.In addition,the rheological analysis demonstrated that temperature,mass concentration,type and concentration of salt ions(Na^(+)and Ca^(2+))had an influence on the changes of the viscosity and shear stress,and their mechanisms were different.As the shear rate increased,the viscosity of ARP solution decreased.The phenomenon of shear-thinning indicated that ARP solution belonged to a non-Newtonian fluid.The analysis results are expected to provide a theoretical basis for the development and utilization of Asparagi radix polysaccharide in food and medicine fields.
作者
李梦钰
刘会平
贾琦
吴亚茹
LI Mengyu;LIU Huiping;JIA Qi;WU Yaru(State Key Laboratory of Food Nutrition and Safety,College of Food Science and Engineering,Tianjin University of Science and Technology,Tianjin 300457,China)
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2021年第5期48-56,共9页
Food and Fermentation Industries
关键词
天冬
多糖
结晶性能
热学特性
理化性质
流变特性
asparagi radix
polysaccharide
crystallization property
thermal property
physicochemical property
rheological property
